文字列大好きいろはちゃんイージー / Iroha Loves Strings (ABC Edition) （优先队列）

题目链接：http://abc042.contest.atcoder.jp/tasks/abc042_b

Time limit : 2sec / Memory limit : 256MB

Score : 200 points

Problem Statement

Iroha has a sequence of N strings S1,S2,…,SN. The length of each string is L.

She will concatenate all of the strings in some order, to produce a long string.

Among all strings that she can produce in this way, find the lexicographically smallest one.

Here, a string s=s1s2s3...sn is lexicographically smaller than another string t=t1t2t3...tm if and only if one of the following holds:

• There exists an index i(1≦i≦min(n,m)), such that sj=tj for all indices j(1≦j<i), and si<ti.
• si=ti for all integers i(1≦i≦min(n,m)), and n<m.

Constraints

• 1≦N,L≦100
• For each i, the length of Si equals L.
• For each i, Si consists of lowercase letters.

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Input

The input is given from Standard Input in the following format:

N L
S1
S2
:
SN

Output

Print the lexicographically smallest string that Iroha can produce.

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Sample Input 1

Copy

3 3
dxx
axx
cxx

Sample Output 1

Copy

axxcxxdxx

The following order should be used: axx, cxx, dxx.

题解：大致意思是是对字符串排序然后顺序输出 尝试用了下字符串的优先队列 以为会哇一发 没想到居然过了 

　　　可是我用优先队列之后 感觉 L 这个数据就废了啊 也没看其他的做法 不知道有没有用它 

#include <iostream>
#include <algorithm>
#include <cstring>
#include <cstdio>
#include <vector>
#include <cstdlib>
#include <iomanip>
#include <cmath>
#include <ctime>
#include <map>
#include <set>
#include <queue>
using namespace std;
#define lowbit(x) (x&(-x))
#define max(x,y) (x>y?x:y)
#define min(x,y) (x<y?x:y)
#define MAX 100000000000000000
#define MOD 1000000007
#define pi acos(-1.0)
#define ei exp(1)
#define PI 3.141592653589793238462
#define INF 0x3f3f3f3f3f
#define mem(a) (memset(a,0,sizeof(a)))
typedef long long ll;
ll gcd(ll a,ll b){
    return b?gcd(b,a%b):a;
}
bool cmp(int x,int y)
{
    return x>y;
}
const int N=10005;
const int mod=1e9+7;
int main()
{
    std::ios::sync_with_stdio(false);
    int n,l;
    cin>>n>>l;
    string a;
    priority_queue<string,vector<string>,greater<string> >q;
    for(int i=0;i<n;i++){
        cin>>a;
        q.push(a);
    }
    while(q.size()>0){
        string b=q.top();
        cout<<b;
        q.pop();
    }
    cout<<endl;
    return 0;
}